Yellow Bullet Forums banner

1 - 20 of 30 Posts

·
Registered
Joined
·
1,269 Posts
Discussion Starter #1
I may be getting an almost new set of FAC 170's from a guy, and of course I can't leave well enough alone... ;)
They're going on a street/strip car BTW, no power adders.
 

·
Registered
Joined
·
324 Posts
How much time are you wanting to spend and how much power are you looking for @ what RPM? In Liberty Dan
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #3
I'm willing to put time into them. These are going on a street/strip daily driver, that will be kept under or about 6K area. They should get here late next week so was planning to disassemble and clean them up, then take a look and see if there are any obvious areas I can make better. How are the factory valve jobs on these? These are supposed to have 3-4K miles on them....
 

·
Registered
Joined
·
1,123 Posts
I got a set a couple years ago that the valve job was off by a solid .020". Had to redo their valve job. Other than that pretty decent little street head.
 

·
Registered
Joined
·
9,666 Posts
Are these heads going on your 418?
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #6
Are these heads going on your 418?
No, I've got a set of canfields for that, Duane Busch ported them. These are going on a street/strip/daily driver car.
 

·
Registered
Joined
·
4,488 Posts
I went 10.24 132 with 170 tw just a good valve job on a pump gas 408. Proper parts selection and they should not need any real work.

Tim
 

·
Registered
Joined
·
9,666 Posts
Stay off the floor and the long wall. Take all the material out of the roof, there's plenty there. Be picky about the valve Job, that head likes a 37-39 degree top angle.
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #9
I got a set a couple years ago that the valve job was off by a solid .020". Had to redo their valve job. Other than that pretty decent little street head.
Thanks, that is what I'll be looking at once I get them apart, I can post some pics up here when I get them.

Any opinion on this bit of info I got from another board

"Intake valve job is a radius and no good for power."
 

·
Registered
Joined
·
9,666 Posts
The intake valve job on that head is not a radius job and the person that made that statement is an idiot. I've seen plenty of valve jobs that incorporated a radius instead of an angle and they did fine.
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #11
The intake valve job on that head is not a radius job and the person that made that statement is an idiot. I've seen plenty of valve jobs that incorporated a radius instead of an angle and they did fine.
HAHA, thanks, I heard the same thing from someone else there too.
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #12
I got the heads and they are now dissassembled, the intake ports are very clean and you can tell they haven't been run very much, the exhaust ports are a little sooty, but not bad. One thing that stands out is it looks like someone did some bowl blending as you can see the burr marks in the area right under the valve, and the lip of the seat going over to the short turn is very smooth.
Once my son gets back with the good digital camera I'll get some pics up, I might not need to do very much with these, it looks like what I was planning to do is mostly done.
 

·
Registered
Joined
·
1,455 Posts
The intake valve job on that head is not a radius job and the person that made that statement is an idiot. I've seen plenty of valve jobs that incorporated a radius instead of an angle and they did fine.
Radius vj exhust = good
Radius vj intake = bad

Way too much back to back testing to prove it works better with angles on intake.

Rich
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #14
Radius vj exhust = good
Radius vj intake = bad

Way too much back to back testing to prove it works better with angles on intake.

Rich
Thanks, that's what I gathered from different articles I've read on the intarweb.
 

·
Registered
Joined
·
4,182 Posts
^^^^^X2^^^^^^
Stick with the basic's, unless your good with the grinder and have a good idea on what to do. Clean it up, measure it out and see where there at. Then go in there with what need's to be done. Not just taking out material. Look at the throat and Bowl area, size it. Then go from there... gasket match and blend it all in. Good luck


T-flow
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #16 (Edited)
Here are the pics, I wasn't expecting there to be some bowl work done on them already, is this something done at the factory? Another thing I noticed is there is a break in the metal where the valve seats meet in the middle of the chamber. Is that an issue?



 

·
Registered
Joined
·
753 Posts
Radius vj exhust = good
Radius vj intake = bad

Way too much back to back testing to prove it works better with angles on intake.

Rich
I just have not seen a discernable difference in power in engines of this type between the 2 valve jobs. It will not be 10's of Hp difference.I agree that the Intake needs not have a radius seat cut but it would not be worth the money spent in return power if the heads do not need a valve job as in his case.
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #18
I got them ported today, didn't do much, just a little bit here and there. For shits and grins I laid a 1415 gasket on the exhaust port to get an idea of how they compared to the ported GT40's I have, and I found that the exhaust port is partially covered by the gasket on the bottom and one side. So, I did the same with a Fel-Pro 351W intake gasket I have and it is similar in that the port seems offset to one side. I can run a 1262 gasket on the intake and that should cure that issue, the exhaust port I can fix by bolting the gasket on, then cutting the gasket to match the port. Just struck me as odd that they would be off by that much. I'll get some pics up later on this weekend or later today if I can find my son's camera in his room.:rolleyes:
 

·
Registered
Joined
·
1,269 Posts
Discussion Starter #19
Here's pics from what I did, as I said before not taking much out at all, I didn't touch the floor on either port, I did work on the exhaust making it a little taller, cut down the pushrod bump a little to make more of a straight shot into the bowl, and worked on the short turn some on both intake and exhaust. Overall, I was just trying to make it a little better, and not booger it up for when they go to get the CNC work down the road.







For shits and grins I measured the volume of the intake and exhaust ports, I came up with 170CC for the intake and 70CC for the exhaust, stock is supposed to be 170/66. I did take out some on each port, but not a huge amount of material out of it. I thought it would at least change some more on the intake though.
 

·
Super Moderator
Joined
·
35,270 Posts
I just have not seen a discernable difference in power in engines of this type between the 2 valve jobs. It will not be 10's of Hp difference.I agree that the Intake needs not have a radius seat cut but it would not be worth the money spent in return power if the heads do not need a valve job as in his case.

I agree with this sentiment.

I've had some very good cylinder heads with radius inlet jobs.

My Victors from Bischoff had radius valve job on the inlet and at the time, circa 2005 they were the best set of victors, likely in existence at that time.... ran very strong.

But, I do prefer an angle cut inlet valve job.
 
1 - 20 of 30 Posts
Top